Add the ratio parts to find the total, then express the asked quantity as a fraction.<br><br>
&bull; Ratio = \(4 : 1 : 5\)<br>
&bull; Total parts = \(4 + 1 + 5 = 10\)<br>
&bull; Belinda = 1 part out of 10 = \(\frac{1}{10}\)<br><br>
Final Answer: a = 1, b = 10